Session: 14-01-01 - New Concepts & Retrofit Solutions

Submission Number: 174239

Risk-Based Design Approval Framework for Dual Fuel LNG Retrofits in Aging Fleets: An Indonesian Maritime Case Study 

The lack of baseline technical documentation in an aging domestic fleet prevents retrofit approval under conventional type-approval frameworks—a "compliance gap." The risk-based strategic framework presented in this paper creates functional safety equivalency without regard to Original Equipment Manufacturer (OEM) compliance through methodical risk analysis. In reality, OEM responses for aging equipment constitute liability, despite traditional frameworks' assumption that OEM conformity offers technical assurance.

The framework was validated for different constraints in two pilot projects. In cramped areas, active barriers with dual gas sensors and forced ventilation (30 ACH) were equivalent to actual airlocks. FMEA effectively lowered residual risk for legacy engines to ALARP levels. Vessel B: 78% for critical modes (24.7 to 5.3); Vessel A: 62% risk reduction (15.8 to 6.0). Both (Vessel A: July 2024; Vessel B: November 2025) received Level 1 Approvals in Principle. Timelines were reduced from 18 months (sequential OEM-dependent) to 6–8 months with a 50–55% efficiency gain thanks to a parallel risk-based workflow. This structure makes Indonesia's domestic fleet decarbonization (Ministry Decree KM 8/2023, IMO 2030 targets) by offering approximately 80% of aging tonnage that is currently ineligible under conventional frameworks for legally defensible retrofit pathways.

Keywords: Maritime Decarbonization, Risk-Based Design Approval, Alternative Compliance, LNG Dual-Fuel retrofit.

Presenting Author: Muhamad Rizqi Fitra Hariadi PT Biro Klasifikasi Indonesia

Presenting Author Biography: M. Rizqi Fitra Hariadi is a Senior Researcher at PT Biro Klasifikasi Indonesia (BKI) with expertise in green ship technology, alternative marine fuels, and maritime GHG reduction strategies. He earned his Master of Engineering in Marine Engineering (Summa Cum Laude) from Institut Teknologi Sepuluh Nopember, focusing on dual-fuel LNG retrofits. His work includes leading Indonesia’s Green Ship Technology Roadmap, developing carbon trading mechanisms for shipping, and conducting Life Cycle Assessment studies. Mr. Hariadi has presented at ISOPE, IMO MEPC, and other international maritime conferences.

Authors:

Muhamad Rizqi Fitra Hariadi PT Biro Klasifikasi Indonesia
Mohammad Arif Kurniawan PT Biro Klasifikasi Indonesia